1. Field of the Invention
The invention relates generally to aerial and die-mount cams and more particularly to improvements in cams configured to provide an increased load-bearing capacity and to facilitate the fabrication of long-lived, narrow cams having components that do not require custom fitting.
2. Background Art
Aerial and die-mount cams are often used to operate tools for such manufacturing processes as punching, trimming, stamping and bending workpieces. These devices include elements that convert downward and upward forces provided by a press into laterally directed component forces that advance and retract a tool in lateral directions to effect the mentioned processes.
Since some manufacturing processes require the application of considerable forces, an important feature of cams is their load-bearing capacity. Cams in present use typically have a maximum load-bearing capacity of some 1.5 tons. Previous attempts to increase load-bearing capacity have included broadening bearing surfaces, but these have increased the width of the cams. Since cam size is a limiting factor that prohibits the use of certain cams in certain presses and for certain applications, it is thus another important feature in cam design and application.
A few of the attempts to increase load-bearing capacity of cams have included the introduction of laterally inclined bearing surfaces. These changes provided an advantage of increasing the stability of the cams as well as somewhat increasing their load-bearing capacities, but they were not directed toward reducing the lateral sizes of cams.
The wearing of parts that are in slidable contact with other parts is always a concern in mechanisms such as aerial and die-mount cams. Having to remove cams from their presses to replace worn parts can be a costly and time-consuming activity.
The structural integrity of joined parts is another important area of concern. Fasteners such as bolts that hold parts together are more likely to loosen or fail if they are placed under stress during press operation.
Many aerial and die-mount cams have configurations that are unique to their use in specific presses and for specific purposes. Their design and construction result in additional expenses.